The invention relates to a constant velocity fixed joint having a bell-shaped outer joint part comprising a hollow space and uniformly circumferentially distributed outer running grooves, and an inner joint part with inner running grooves corresponding to the outer running grooves, as well as torque transmitting balls received in the inner and outer running grooves and held in the windows of a cage arranged between the outer joint part and inner joint part, the inner joint part, with a stop face associated therewith, being supported axially inwardly in the hollow space of the outer joint part on a corresponding stop face.
The inner joint part is known to be axially inwardly supported in the hollow space of an outer joint part (DE-0S 3 114290), the object of such a solution being to provide a distance between the outer face of the inner joint part and the inner face of the cage, thereby eliminating the need of machining the inner face of the cage and the outer face of the inner joint part.
The disadvantage of the above-described solution is that the inner face of the outer joint part still has to be subjected to an expensive machining operation and that the joint has to be built with overly tight tolerances and conforming surfaces on the mating parts.
It is the object of the present invention to provide a constant velocity fixed joint in the case of which all expensive machining operations on the inner faces are eliminated, with friction and thus rises in temperature being reduced considerably. Furthermore, the requirement of overly tight tolerances and conforming surfaces of mating parts of the joint is to be avoided.
In accordance with the invention, the objective is achieved in that the cage is controlled exclusively via the balls and supported axially outwardly via an axially limited annular region positioned at the open end of the hollow space, the cage otherwise being arranged at a distance from the inner face of the outer joint part and from the outer face of the inner joint part, the advantage of this design being that only the outer face of the cage needs to be machined. Furthermore, this design avoids any kind of excessive friction due to overly tight tolerances and conforming surfaces of the joint which may occur when the respective faces carry their loads and which would otherwise lead to high friction losses and the development of heat. The risk of jamming when the joint is articulated is also avoided without fail.
In an advantageous embodiment of the invention, the annular region is formed by wedges welded to the outer joint part between the outer running grooves under inwardly directed pressure applied during the assembly of the joint.
By welding on the wedges under an inwardly directed pressure applied during the assembly of the joint, it is possible, at the same time, to set the joint in respect of defined play values.
According to a further essential feature of the invention, the annular region is formed by radially inwardly directed guiding faces arranged between the outer running grooves.
According to a further advantageous feature of the invention, the spherically designed second stop face is determined by a radius whose center is arranged at a distance from the center line, with such radius being greater than the radius provided at the axial inside of the inner joint part and being the radius of the first stop face.
In a further embodiment of the invention it is proposed that the second stop face should be formed by a cone.
In a further embodiment of the invention it is proposed that the spherically designed first stop face should be arranged so as to be integral with the inner joint part, with supporting contact being provided between the inner joint part and the second stop face.
This design constitutes a particularly compact version of the joint in accordance with the invention.
According to a further essential feature of the invention, the spherically designed first stop face is arranged in the form of a separate part-spherical head at the end of the inner joint part facing the inside of the hollow space and that there is provided a distance between the inner joint part and the second stop face.
With this embodiment there is plenty of scope for designing the inner joint part.
According to a further advantageous embodiment of the invention, the part-spherical head is centered relative to the inner joint part via centering means.
With this design, the part-spherical head is secured perfectly against any eccentric displacement.
According to a further essential feature of the invention, the second stop face is formed by an insert arranged on the axial inside of the hollow space and radially movable to a limited extent.
With this design there is no need for machining the spherically designed contact face inside the hollow space.
According to a further advantageous feature of the invention, the insert is accommodated in a recess which is arranged on the axial inside of the hollow space and whose diameter is greater than that of the insert. In particular, this design is intended for joints provided with an offset.
This embodiment is advantageous in that the Spherical contact face of the insert may be produced by deformation.
In a further embodiment of the invention, the second stop face is designed as a planar face.